In order for electronic devices to communicate, a wireless or wired protocol (i.e., standard) defines hardware and software parameters that enable the devices to send, receive, and interpret data. Frequency division multiplexing or frequency division modulation (FDM) is a technology that transmits multiple signals simultaneously over a single transmission path, such as a cable or wireless system. Each signal travels within its own unique frequency range (carrier), which is modulated by data (e.g., text, voice, video, etc.).
Orthogonal FDM (OFDM) distributes the data over a large number of carriers that are spaced apart at precise frequencies. To mitigate multi-path energy and to enable a transmitter and receiver to switch between different frequency bands. Some wired and wireless protocols define a guard interval that is placed before transmitted information symbols as a prefix. Other protocols define a guard interval that is placed after transmitted information symbols as a suffix (e.g., a zero-padded suffix or “ZPS”). In either case, the guard interval reduces interference between information symbols by providing time for multi-path reflections to attenuate.
When a ZPS is used (e.g., in a Multi-Band Orthogonal Frequency Division Modulation (OFDM) system), a receiving device may use an “overlap-and-add” operation to add samples of the ZPS to samples of the symbol preceding the ZPS. For example, the overlap-and-add operation may combine the “N” samples of the ZPS with the first N samples of the symbol preceding the ZPS. In some overlap-and-add operations, the entire symbol preceding the ZPS is buffered and the Fourier Transform logic of the receiving device is prevented from processing samples of the symbol until after the overlap-and-add begins. Accordingly, the overlap-and-add operation introduces undesirable latency at the receiving device.